This invention relates generally to an electrophotographic printing machine, and more particularly concerns a floating high voltage connector to enable movement of transfer module after electrical connection has been made.
The marking engine of an electronic reprographic printing system is frequently an electrophotographic printing machine. In an electrophotographic printing machine, a photoconductive member is charged to a substantially uniform potential to sensitize the surface thereof. The charged portion of the photoconductive member is thereafter selectively exposed. Exposure of the charged photoconductive member dissipates the charge thereon in the irradiated areas. This records an electrostatic latent image on the photoconductive member corresponding to the informational areas contained within the original document being reproduced. After the electrostatic latent image is recorded on the photoconductive member, the latent image is developed by bringing toner into contact therewith. This forms a toner image on the photoconductive member which is subsequently transferred to a copy sheet. The copy sheet is heated to permanently affix the toner image thereto in image configuration.
Multi-color electrophotographic printing is substantially identical to the foregoing process of black and white printing. However, rather than forming a single latent image on the photoconductive surface, successive latent images corresponding to different colors are recorded thereon. Each single color electrostatic latent image is developed with toner of a color complementary thereto. This process is repeated a plurality of cycles for differently colored images and their respective complementary colored toner. Each single color toner image is transferred to the copy sheet in superimposed registration with the prior toner image. This creates a multi-layered toner image on the copy sheet. Thereafter, the multi-layered toner image is permanently affixed to the copy sheet creating a color copy. The developer material may be a liquid or a powder material.
In the process of black and white printing, the copy sheet is advanced from an input tray to a path internal the electrophotographic printing machine where a toner image is transferred thereto and then to an output catch tray for subsequent removal therefrom by the machine operator. In the process of multi-color printing, the copy sheet moves from an input tray through a recirculating path internal the printing machine where a plurality of toner images is transferred thereto and then to an output catch tray for subsequent removal. With regard to multi-color printing, a sheet gripper secured to a transport receives the copy sheet and transports it in a recirculating path enabling the plurality of different color images to be transferred thereto. The sheet gripper grips one edge of the copy sheet and moves the sheet in a recirculating path so that accurate multi-pass color registration is achieved. In this way, magenta, cyan, yellow, and black toner images are transferred to the copy sheet in registration with one another.
In connection with the invention, there is provided an apparatus for advancing a sheet through a transfer zone and into registration with information developed on a moving member. This apparatus is arranged in a module which can be removed from the main machine to remove the jammed sheets or for other maintenance. The module includes a corona generating device which sprays ions on the back side of the sheet so as to charge the sheet to the proper electrostatic voltage magnitude and plurality for attracting toner image from the photoconductive belt. An electrical connector is provided on the module for connecting the corona generating device to a power source in the main machine. A high voltage connector for this purpose is mounted in the rear of the main machine for connection and disconnection with the corresponding connector on the transfer module. When the drawer is opened to clear jammed paper, the electrical connection can be disconnected when the drawer is pulled out and away from the rear of the machine. For this purpose the machine connector and the module connector must register to ensure that electrical engagement between the operative part is obtained.
In the invention described herein, the position of the connector on the transfer module is such to permit connection for electrical engagement, but once in this position the module is raised slightly to contact the photoreceptor module. Thus, the connector in the main machine must be movable between a lower position where the connection is made and an upper position when the transfer module is raised to contact the photoreceptor module. This positioning is critical to copier quality and dependent upon the ability of the transfer module to move as described. Any forces which inhibit this movement detract from the proper operation of the machine and the ultimate quality of copy produced.
Other features of the present invention will become apparent as the following description proceeds and upon reference to the drawings.